draft_genome_fasta

Eleven clonal strains of 9 Skeletonema species were established from a bloom in various regions in Japan, Vietnam, China, Taiwan, and Sweden by micropipetting single chains. Sequencing of DNA and RNA was performed using the Novaseq 6000 (Illumina, San Diego, CA, USA) or DNBSEQ-G400 (MGI Tech, Shenzhen, Guangdong, China), the next-generation sequencers. For genome sequencing, library construction of Pair End libraries (150PE) were performed by the default protocol and these libraries were used for sequencing. A total of 9.1–30.0 Gbp of sequences were obtained, which were approximately 131–644 x coverage of Skeletonema genomes (40.3–69.3 Mbp, see below). For long-read sequencing using MinION (Oxford Nanopore Technology, Oxford, UK), a total of 1.1–22.1 Gbp of long-read data were obtained, which were 20–445 x coverage of Skeletonema genomes.
We applied a hybrid de novo assembly approach based on Illumina short-reads and Nanopore long-reads. Short– and long–reads were assembled to contigs using MaSuRCA v4.0.8. For gap-closing, assembled contigs were scaffolded into the draft genome using HaploMerger2 v20180603. The resultant draft haploid genomes had total lengths of 40.3–69.3 Mbp, scaffold numbers of 94–348, N50 of 0.35–1.09 Mbp, and the longest scaffold of length 2.1–4.6 Mbp, as calculated by QUAST v5.1.0rc1.